


Split My Heart In Two And Take Your Side Across The Rift

by ZaraMelMercury



Series: Split My Heart In Two [1]
Category: Captain America (Movies), Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Alpha Natasha Romanov, Alpha Steve Rogers, Alpha/Beta/Omega Dynamics, Angst, Attempt at Humor, Cheating, Emotional Hurt/Comfort, Fluff, Hurt Tony Stark, Knotting, M/M, Natasha Romanov Is a Good Bro, Omega Bucky Barnes, Omega Tony Stark, Post-Serum Steve Rogers, Protective Natasha Romanov, References to Knotting, Steve Rogers Needs a Hug, Tony Stark Needs a Hug, Tony Stark-centric
Language: English
Status: Completed
Published: 2021-01-05
Updated: 2021-01-05
Packaged: 2021-03-15 17:35:53
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 3,074
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28567833
Author URL: https://archiveofourown.org/users/ZaraMelMercury/pseuds/ZaraMelMercury
Summary: Tony has been working non-stop for SI for over a month now and he feels guilty for neglecting his Alpha, Steve Rogers.He's booked a surprise trip for the both of them as an apology gift, but when Tony arrives at home to surprise his mate, everything falls apart for him.
Relationships: Natasha Romanov & Tony Stark, Steve Rogers/Tony Stark
Series: Split My Heart In Two [1]
Series URL: https://archiveofourown.org/series/2095461
Comments: 34
Kudos: 182





	1. Chapter 1

**Author's Note:**

> So, this is another ficlet I came up with and it's my first A/B/O fanfic, so I played around with the technical side of things and tried to make the biology behind it as sensical as possible. I tried to go for heavy angst, but I think it fell flat, because I can't write unhappy endings for the life of me😂
> 
> But, I do hope it has enough drama for your fulfillment, so please enjoy!

Tony could hardly contain his excitement any longer as he leapt up the front doorsteps of his home!

He felt it as it started bubbling up in **_snaps_!** **_crackles_! **and _**pops!**_ until it broke free in his gleaming smile!

The genius had been working non-stop for SI for over a month now and it had taken quite a toll on him. And on Steve especially. With all the work piled up, Tony hadn’t been able to show his alpha the love and affection he’d normally be able to give.

No late-night cuddles on the couch, wrapped up in each other’s warmth. No lounging late in bed as they watched sappy rom-coms. And no sweet, little moments of feeding each other bites of their breakfast in the mornings.

And Tony believed that he’d be a bad partner if he didn’t feel bad enough to make it up to Steve! 

So, he’d gone and booked the both of them a surprise two – week trip to Italy!

They both needed a break and Tony couldn’t wait to spoil his alpha with the huge number of sightseeing tours, multiple platters of foods from his favorite Italian restaurants and endless hours spent on their own private section of the beach. He’d supervised the renovation on their beach house, personally, to make it as artistically perfect as possible so that it suited Steve’s taste so he’d be able to sketch peacefully by the sea.

Tony had it all planned out and even managed to talk Fury into letting them take the trip.

Now, all that was left was to tell his mate!

He swung open the front door - with the absolute _most_ _dramatic_ flourish! - and called out to the love of his life joyously, “Steven! Oh, Alpha of my Eye-“

And hearing how awful the flirtatious comment was, it made Tony then flinch in embarrassment! 

He rubbed the back of his neck and subconsciously continued rambling as he jogged up the stairs, “Okay, okay, yeah, that’s- that’s actually _not_ my best moment, Honey, but you get my point anyway. _And..._ you agreed to this mess, that is me, but this mess has **the** **most** _**AMAZING**_ gift in the history of make-up presents.“

He paused on the landing, shrugging off-handedly, “Maybe. I don’t know... I’m not really sure. I don’t even know if you’ll like it, but I’m just so happy to be home and see you!”

Tony leapt up the last few stairs, two at a time, clutching the bouquet of Steve’s favorite flowers and the holiday brochure hidden between the petals. 

“My Sugar-sweet Honeybear, you will _not_ believe the surprise I have planned for us! I totally have F.R.I.D.A.Y on record to capture your face when-“

As he pushed open the door, Tony expected Steve to be lounging on the mound of pillows like the oaf he could be.

But the bouquet slipped from Tony’s hands and it silently fell to the floor. 

The brunette was greeted with another sight entirely. And the scene before him was like a sharp and jagged pointed icicle piercing at his heart.

The bedsheets were thrown askew.

And Steve was naked.

But he wasn’t the only one…

“Ss- Ste-eve? S-Steve is- is…? Are- are you--?” Tony’s voice was but a mere meek whisper as he witnessed his mate make love to another omega not even 7 feet away from him!

_‘Oh my God…’_

The sensual moans and grunts flooded Tony’s ears as he stood frozen to the spot and he feebly wrapped his arms as tight as he could around his mid-section. He tried to keep his body from shattering into glass pieces. The air was fully knocked out of him. He felt so dizzy and confused.

He felt so numb.

And so cold.

It stung everywhere.

“S-Steve?” Tony tried again, his voice a bit stronger, but it still came out as a tiny mouse’s whimper.

Finally, the strange omega turned his head towards Tony, his eyes still closed from pure bliss, but once they opened, the pair of steely grey-blue eyes focused on Tony.

_**Barnes?!** _

Tony’s wide eyes met Bucky’s shocked expression. He froze beneath Steve. A millisecond passed in which a kaleidoscope of emotions passed between both of them.

The tension thickened in the room; wound up tight as a coil.

“Steve,” Bucky’s thin voice was the only sound to break through in the room as he tried to bring Steve’s attention to the situation.

“Mmnf, yeah Buck?” the alpha moaned in ecstasy. He loosely untangled his limbs from Barnes and stretched out his limbs lazily.

Tony’s face heated.

He could smell Bucky’s slick and Steve’s spend as their bodies separated.

_Steve had knotted Bucky!_

The pheromones swirled around the room and he couldn’t escape the smell in any way.

Tony felt nauseous. And confused.

Hot, angry tears gathered in his eyes and his vision blurred over. He sniffled, but immediately brought his hand to his mouth to mute any further noises, but Steve had heard.

Steve heard it.

The alpha slowly turned his body, and came face to face with Tony, stricken and shivering with shock.

“T-Tony, I – you’re- I, uh-“ Steve stuttered helplessly. His whole body flushed with cold embarrassment. His heartbeat picked up erratically.

Scrambling up, off the bed and fumbling for his underwear, the blonde’s whole being was plummeted into the reality of what was happening. Bucky hastily covered himself and simultaneously looked for his clothes too.

Tony remained frozen stiff. He was grasping at his chest desperately, trying to breathe in oxygen. But his body wasn’t working. He was hyperventilating. Tony couldn’t breathe. He couldn’t focus. His head was spinning. His vision became more blurry. Tony’s chest was splintering under the kilogram of lead that seemed to hold him down.

But then the feeling changed drastically within a second.

Tony suddenly felt like he was no longer there. He was floating instead. He was floating light on the wind. His soul was ascending beyond his body.

Tony couldn’t recognize the man before him.

_His Steve-_

**His Steve** was -?

He was—

And- and with _Bucky-!_

“W-were y-you – you a-and – and h-him-?” his voice came out tight, and quavering as he looked between Steve and Barnes “Your… you’re kn-knot- I can… I can sm-smell the—the scent, but – you-? You gave him… your kn-knot?”

An alpha’s/ beta's knot wasn’t just something that you experienced with sex any day of the week. It symbolized much more.

When an alpha or a beta would give their knot without protection, it meant that both partners fully trusted each other and were ready to take their relationship to the next stage.

Having your alpha partner knot you, meant that you both fully trusted each other and your partner was willing to help you through your heat. It meant that you both were ready to bond and start a family.

It signified a new reality that was taking place. There wouldn’t be a pill that had to be taken, it wouldn’t have to be just meaningless sex to satisfy needs whenever both partners engaged in physical matters.

It was a new physical bond that was made. An omega trusting an alpha to take care of him/her. Because it all solely involved the omega. The _omega_ went through their heat. The _omega_ had to carry the pups. For an alpha to give their knot without protection was something sacred. They were ready to start a family.

Even female betas and alphas had the genetic ability to change their reproductive body parts in order to be compatible with their omega partner to take care of him/her during heat. 

Tony and Steve hadn’t even shared that experience yet.

And yet Steve had just… he’d just given it away to Barnes.


	2. Chapter 2

Tony’s ears rang and his vision clouded over with watery tears.

He couldn’t believe it. He didn’t even _want_ to believe it!

Steve was carefully making his way over to Tony, bent low, so as not to frighten his mate.

But Tony wouldn’t have it any more! He couldn’t **stand** **it** in there anymore!

The genius was much faster and he bolted straight out of the bedroom!

“Tony, wait! Wait, _please!_ ” Steve chased after the brunette but Tony had already locked himself in the bathroom. He’d enabled the alpha reinforced door layer too.

“Hon- Honey, please! _Please_ , let me in,” Steve pleaded. He rested his palm against the door, hoping to reach out to Tony through the wood. “Let me please explain, I- I-“

Spluttering sobs could be heard on the other side of the door and Steve’s heart tightened in iron chains. He’d made Tony cry!

And he’d vowed that he’d never let that happen.

“Oh Honey- Honey, _no_ , please – please don’t cry. Please, I **hate** to hear you cry. _Oh, Baby_ … you have no idea how stupid and- and worthless I feel. I’m _so_ incredibly sorry, Baby! I’m _so_ sorry,” Steve rested his forehead against the door, his palm still resting on the wood next to his head. 

Tony’s heaving cries were like a repeated blow to Steve’s body. It pounded against his stomach; knocking out his every breath.

Tony was curled into a ball, resting against the other side of the door and trying to snuffle his wails. His breathing increased. His head felt light. It felt numb. Everything felt numb. It was the type of numbness you would feel when the cold stings so badly, that your nerves finally give up trying to aid you in touch. It was fear creeping in like ice in his veins and sending shockwaves through his body. Tony was hyperventilating. He believed Steve didn’t want him anymore. That he had failed as a partner.

_‘I f-failed and- and St-Steve’s done with me… He gave Barnes his-‘_

Hacking coughs heaved through him as Tony let his sobbing echo off the bathroom walls. He clutched at his chest desperately, hoping that the pain would stop. His throat burned as he tried to swallow his tears thick as steel.

“I- I’m not g-good en- enough! I- nhgh- I’m not ‘ _hic_ ’ no… “ Tony shook his head as he tried to get rid of these thoughts, but they prevailed.

_‘Steve thinks you’re **trash**. You're so easily replaceable, Tony! You’re a **worthless** , no-good omega who purposefully neglects their alpha because of your own **selfish** reasons!’_

Steve’s small voice flowed through the door, trying to reach his mate, “Oh, Sweetheart, please, I- Babydoll, can I please see you? Can you let me in?”

His throat felt thick and strangled with salty tears, “I am _so_ **terribly** sorry, Tony, I- I have no idea what came over me, but it- it wasn’t what you think. I had protection and Bucky is on the pill. We didn’t go further into that bond. I didn't, I **promise!** I just… will you _please_ open the door for me, Doll? ”

Steve’s own tears fell as he pleaded quietly with Tony. He tried to keep his voice controlled, but his own whimpering soon rose from his chest.

His tone turned thin and strangled, “Honey-“

Rocking back and forth, Tony’s sobbing went down to just a few hiccups. Hot, salty tears still stung his eyes and his nose was red and snotty.

“You don’t want me anymore, Steve,” he whispered more to himself, but Steve could hear it through the door. His heart cracked even further.

“No, _**of course**_ I want you, Sweetheart! I want you more than anything Doll! I don’t deserve to have you... You are the _**best**_ thing that’s ever happened to me… “ the blonde’s voice turned regretful, “I just... I didn’t see it because I became too selfish… I didn’t think…”

Steve’s eyes screwed shut tight as he fought back more falling tears, “Just _please,_ my sweet baby, _please_ open the door for me. I need to see you – I need to apologize to you properly. Babydoll? Tones, please.”

Steve’s forehead rested despairingly against the hardwood as his shoulders hitched with his quiet sobs.

“Please Tones, I really still need you…” he croaked out.

“Steve”

Looking up, Steve saw Bucky with his own tears in his eyes. He'd probably figured out, or he remembered what Steve did to him before this happened.

The two friends had gone out for drinks, because Steve had felt pretty petty, like a child, and he wanted to get drunk and forget about his selfish feeling of loneliness.

A devilish thought had then come into Steve's mind at the bar. He decided to get Bucky drunk enough to agree to blind sex. One thing then led to another and...

Bucky's jaw was clenched tight as he looked away from Steve to the door. He was seething in his weeping cries through his clenched teeth, as his tears fell like silent waterfalls over his face.

Bucky threw an understanding look towards the bathroom door.

“We should give him some space. It’s no good trying to talk things out now,” he bent his head solemnly, running his sleeve over his teary eyes, “I know I'm gonna figure something out that's worthy of an apology- I don't know about you."

He shot Steve a pained look of disbelief.

_'I don't know who you are anymore, Stevie.'_

"But right now," Bucky continued," he won't want to listen to anyone. And we're in no good condition to reason with each other. I'm certainly not, with what you did to him and me. But I guess I should be used to being used and manipulated... And I don't even know why, but I'll at least make you some tea before I go.”

Bucky shook his head. "Maybe I wanna make sure I still have a **heart** ," he shot at Steve, dryly.

He made his way towards the kitchen. The blonde sighed.

_'What on Earth have I done?...'_

He gave the bathroom door one last pained look before heading downstairs in defeat.

Tony still couldn’t think. His brain refused to work. It was in a glitch. It was like hitting a brick wall every time. Everything was so confusing.

He walked in on Steve-

He was convinced Steve didn’t want him anymore, but then he started apologizing. Should Tony believe him? Was Steve being sincere? How could he know if he could trust his mate again? How could Tony ever believe Steve again after something like that? But shouldn’t everyone get a second chance? Was Tony truly a bad mate for not hearing Steve’s side to the story? But what side could there be? Steve felt neglected and bored with Tony, so he moved on to someone he loved more. But some other part of Tony was trying to convince him that Steve wasn’t like that.

It was all too much. He just needed to get out!


	3. Chapter 3

When Natasha heard the doorbell ring, she smiled helplessly to herself. 

Making her way to the front door, she feigned a scolding tone as she opened to let Tony in.

“ _Really_ , Tones, no matter how many times you do it, I still think getting voice-mails from AIs is weird!” she chuckled, expecting to see Tony smirking right back at her in his suit.

But instead, she saw a tiny human frame curled up in a ball on her front doorstep.

Nat furrowed her brows, confused. She knew it was Tony, but this concerned her deeply now.

“Tony? Hey, what’s going on?” she knelt down and spoke in soothing tones, reaching out to touch his shoulder gently, “Kotynok, what are you doing on the ground? Come on inside – I’ll make us two cups of your favourite coffee.”

Natasha gently pulled Tony up onto his feet and guided him into her house. Tony felt weightless. His limbs fumbled loosely like noodles and he couldn’t seem to focus on anything. His gaze was far away. Nat saw how bloodshot his eyes were. His nose was still red and runny and tear tracks stained his cheeks.

She sat him safely on the couch and went to check on the coffee in the kitchen. Thankfully, since F.R.I.D.A.Y alerted her ten minutes before the time that Tony would be coming by, his coffee was basically finished brewing.

She walked back into the living room and saw Tony slouching in the same position she left him.

All the spark was sucked out of him. His eyes were dull and lifeless. It was terrifying to watch.

She gently placed a hand to the side of his face, moving his head slightly to focus on her.

“Tony?” she spoke again, softly.

It took a while, but slowly, his eyes lost their haze and Tony blinked a couple times before really seeing Nat in front of him.

“Natasha…” he breathed out, defeated.

It sounded so much like a plea. He needed someone he knew would help him without asking too much or crossing over boundaries. Natasha understood.

Most people would grow to see you in a different light when troubles come your way. When you asked for help, some people would believe you to be too frail or sickly to handle something like that on your own ever again. Natasha wasn’t like that. She didn’t push or fawn over you like an injured duckling. She understood that each person had to overcome their own battles, but she’d be there to catch you nevertheless.

And Tony saw it from her days as Natalie Rushman.

He tentatively held his arms out, asking silently for a hug. Nat smiled warmly at Tony and pulled him into her arms, kissing his forehead.

“I’m guessing Steve doesn’t know you’re here then?" she murmured, stroking through his curls.

Tony smiled feebly, “No, I uh… I flew out the window.”

The red-head rolled her eyes and giggled at the small genius.

Tony would fall asleep soon, like he always did when she petted him like this, and then she’d deal with a _certain_ blonde responsible for putting her friend in a state like this!

But for now, she held on to Tony and soothed him quietly.

“We’ll work it out together, Antoshka. We always do," She rubbed his back reassuringly," And you’ll be alright. I’ve got you right here in my arms.”

She gave Tony one last peck on the forehead and soon enough, quiet snores began to fill the living room. She rested Tony’s head in her lap and pulled a blanket over his sleeping form.

“Oh, Steven Rogers, you are **_so_ dead!**” she muttered.

**Author's Note:**

> Kudos are always much appreciated and share my work if you liked this one❤️


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